Sender Policy Framework (SPF) is a type of DNS record that identifies which mail servers are permitted to send emails on behalf of your domain.
The purpose of an SPF record is to prevent spammers from sending messages with forged From Addresses at your domain.
If your domain does not have an SPF record some recipient domains may reject messages because they cannot validate that the message is coming from an authorized mail server.
With this being said, if you are concerned that your emails are being sent to recipient's spam folders you can try adding the following SPF record in your DNS.
HOST: example.com (your domain)
DATA: "v=spf1 include:_spf.wishpond.net include:sendgrid.net ~all"
Not sure what this means? Send this to your web developer, or contact us at email@example.com for more help.